Heretofore, it has been conventional practice to make water-insoluble resinous polyelectrolyte by various emulsion, suspension, solution, or bulk polymerization processes, then to disperse or dissolve it in aqueous medium by adding an appropriate ionizing agent, either basic or acidic. The instant process not only manifestly saves such post-polymerization dispersing or dissolving step, but also produces a resinous polyelectrolyte with a narrower molecular weight distribution than most corresponding solution or bulk polymerizations (no high molecular weight "tail"), and a lower average molecular weight than a corresponding emulsion polymerization, while also eliminating the surfactant required in emulsion or suspension polymerization. The instant polymerization does not appear to be diffusion controlled as are emulsion polymerizations, nor is it truly typical of a solution or bulk polymerization operation, although it might be theorized as a new type of dispersion polymerization with water as the vehicle for the resulting ionized electrolyte.
The aqueous dispersions of polyelectrolytes produced by this process are particularly useful in coatings to be applied by electrophoretic deposition. Products of this process can be useful for coating various substrates, e.g. sanitary coatings for metal cans or coatings for wood.